This invention relates to a bike inner derailleur, particularly to one having a simple structure, easy to handle, a wide speed changing scope, a small dimensions, and a lightweight.
A bike inner derailleur is a speed changing structure installed in a wheel hub, achieving speed changing and saving time and force by means of gear proportion of the gears groups therein and choosing transmitting routes of the gear proportions. A conventional bike inner derailleur includes a planet gear group, a power input source, crutches in a single direction, a power stopping structure and springs, related input and output rods, etc. Utilizing the power source input and choosing the power transmission routes can obtain at least one or more different speed proportion outputs. The idea of the planet gear groups was disclosed as early as in 1880, and a sun gear was added to the planet gear group in 1895, for driving a bike, and in 1896 a really commercialized inner derailleur was disclosed, having a lever for controlling control rods fixed in a hollow rod and sliding movement of the sun gear for acquiring different speed proportions. So far conventional inner derailleurs have been made to have three, four, five, seven and twelve speeds, and an outer derailleur of seven speeds and an inner derailleur of three speeds.
As to the inner derailleur for bikes, many patents have been disclosed in U.S. Pat. Nos. 4,842,291, 4,854,191, Re.33058, 4,947,703, 4,973,297, 5,011,464, 5,069,655, 5,078,664, 5,083,991, 5,236,403, 5,273,500, 5,273,501, 5,318,486 5,322,487, 5,378,201, 5,399,128, 5,443,279, 5,445,573, 5,469,755, 5,527,230, 5,556,354, 5,540,456, 5,556,354, 5,590,894, 5,769,750, 5,785,625, 5,829,563, 5,833,040, etc.
In general, an inner derailleur disclosed in those cases has a narrow scope for weight, dimensions, and speed proportion, not adaptable for race bikes or mountaineering ones, almost used in cities for going to work, for bikes with a motor, and collapsible bikes. It has a complicated structure, many components, a heavy weight, a large dimension, and a limited scope of speed proportion selection. In technological principle, they have used planet gear groups of a little modification, and have different designs in the control structures and the gear transmission.
The technological bottleneck at present lies in making a bike inner derailleur of a simple structure, an easy operation, a wide speed proportion scope, small dimensions, and a light weight.
This invention has been devised to offer a bike inner derailleur of a simple structure, having a wide speed change scope, small dimensions, and a light weight.
The feature of the invention is a flat projecting wheel provided with a plurality of annular grooves of the same center and a plurality of control rods. A certain angle rotation of the flat projecting wheel can move at least one or more of the control rods, to operate single direction clutches (or detents) of the speed changing structure.
Comparatively many control rods are fixed around on a circular outer surface of a fix shaft for producing a more speed proportion scope. In addition, an intermediate ring is provided between two gear groups for producing manifold power transmitting routes for selection so that a bike inner derailleur may have a simple structure, a small dimensions, a light weight, and easy to handle in selecting one of many speeds. The Figures show an embodiment of a bike inner derailleur having 13 stages of speed proportion outputs.